Packaging of liquids

ABSTRACT

The invention concerns a method and apparatus for packaging a liquid. The liquid is fed portion-wise through cooling means to produce frozen solid entities which are transferred to apparatus which applies a substantially even layer of coating material over the surface of the entities, the coating material being thereafter induced or allowed to solidify and the frozen contents to melt, whereby sealed containers with liquid contents are produced.

United States Patent [191 Horsewell et all [111 3,830,079 [451 Aug. 20, 1974 PACKAGING 0F LIQUIDS Inventors: Henry George Horsewell, Totton;

Arthur John Terry, Southampton,

both of England Brown & Williamson Tobacco Corporation, St. Louisville, Ky.

Filed: Aug. 27, 1973 Appl. No.: 391,688

Related US. Application Data Assignee:

Continuation of Ser. No. 249,737, May 2, i972, abandoned, which is a division of Ser. No. 22,354,

March 31, 1970, Pat. No. 3,693,369.

US. Cl. 62/322, 425/6 Int. Cl. F25c 1/00 Field of Search 62/l, 60, 322, 74, 123;

References Cited UNITED STATES PATENTS Clement 264/13 Gunnell 264/4 2,751,762 6/l956 Colton 62/347 X 2,93l,067 4/l960 Delaloye et al 264/l3 X 3,297,799 l/l967 .lackun et al 264/l4 3,313,032 4/l967 Malecki 34/5 7/l967 La Grange 264/l3 X Primary ExaminerWilliam E. Wayner Attorney, Agent, or Firm.Kane, Dalsimer, Kane, Sullivan and Kurucz [5 7 ABSTRACT 4 Claims, 6 Drawing Figures PATENTEDmszo 1974 3,830,079

1 PACKAGING or LIQUIDS This is a continuation of US. Pat. application Ser. No. 249,737, now abandoned filed May, 2, 1972 which in turn is a divisional appl. of US. Pat. Ser. No. 22,354 filed Mar. 31, 1970, now US. Pat. No. 3,693,369.

This invention concerns the packaging of liquids, particularly but not exclusively the packaging of liquids in capsules which are required to be readily opened by digital pressure.

Sealed containers, such as glass ampoules or plastics sachets, which protect their contents against spillage and deterioration, can be used for aqueous liquids, but have the disadvantage that they may be difficult to open in circumstances where ready opening by. digital pressure alone is required. Also, the material of such containers may be inherently unsuitable for some purposes, for instance if they are required as components to be used in moistenable tobacco-smoke filters.

An object of the present invention is to provide means whereby liquids can readily and easily be totally enclosed in packages which are rupturable under digital pressure.

According to the invention,-a liquid which is required to be packaged is fed portion-wise through cooling means to produce frozen solid entities, possibly of sub- -stantially spherical shape, which, after removal from the cooling means, are transferred to apparatus which applies a layer of coating material substantially evenly over the surface of the solid entities, the coating material being thereafter induced or allowed to solidify and the frozen contents to melt, whereby sealed containers with liquid contents are produced.

Preferably, the cooling means may comprise a cold liquid or mixture of liquids through which the liquid to be packaged is passed and which is substantially immiscible with, and of substantially lower freezing point than, the liquid to be packaged. Additionally, the cooling means should not only be of viscosity such that undue turbulence is minimised in the portions of the liquid to be packaged, but also of greater density than this liquid. The combination of these two physical properties may be used to control the rate of movement of the portions through the cooling means.

Advantageously, the coating material isapplied by means of two coacting, parallel, horizontal rollers rotating in the same direction above a bath of the coating material into which at least one of the rollers dips, the frozen entities being supplied to the upper bight between the said rollers. One of these rollers may be helically grooved around its periphery, while the periphery of the other may be provided with shallow grooves substantially parallel to the axis of rotation. Portions of the material are picked up by the shallow grooves and deposited on the frozen entities in the aforesaid bight. The coating material may be a synthetic or natural wax, such for instance as paraffin wax, or a plastics material or a mixture thereof, which will form over the frozen liquid a continuous even coating which can be hardened to form a rupturable or friable sealed container. It may be applied as a solution, suspension or emulsion, or in molten form.

One manner of carrying the invention into effect upon a small-production scale will now be more fully described by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatic illustration of an apparatus for producing small balls of ice,

FlG.. 2 a perspective view of an apparatus for waxcoating the said balls, 7

FIG. 3 a plan view of a part of the latter apparatus,

FIG. 4 a part-section on the line IV-IV in FIG. 3,

F IG. 5 is a view similar to FIG. 3 illustrating a modification, and

FlG. 6 a transverse vertical section thereof.

The apparatus for producing ice balls shown in F IG. 1 comprises a column or tower 1 formed by a thermally insulated vertical glass tube, 4 inches in diameter and 8 feet high, filled with a mixture of 1,1,1- trichloroethane (approx. 60 percent) and n-hcxane (approx. 40 percent) having a specific gravity of 1.09 at C. The evaporatorcoil 2 of a cooling system comprising a condensing unit 3 is located on the inside of the wall of the column 1, where it is immersed in the mixture. The condensing unit operates with Freon-22 and has a-rating of horse power. The system maintains the temperature of the mixture in the column 1 substantially constant at 25 C.

Water containing 1 /2 percent glycerine is injected in drops through a jet or nozzle 5 of 1.2 mm. dia. in the base of the column 1 under a head in excess of the pressure of the mixture there. For this purpose, the water i is supplied from tank 6 mounted approximately 1 1 feet above the said base. A needle valve 7 regulates the flow of water into the column I, the rate of flow being measured by a standard flow-meter 8. The jet-5 is screwed, so as to be replaceable, into a block 9 which can be maintained at a temperature of approximately 50 C by means of a small electrical heating element 10, whereby the water is prevented from freezing in the jet. This heater can also be used for initially unfreezing water in the jet 5 after an inoperative period. A gate valve 11 is also incorporated in the block 9, so that the jet can be removed without draining the column. Due to their lower specific gravity, the water drops leaving the jet 5 pass up through the mixture in the column 1 and become frozen into ice balls 12. These ice balls 12 pass into an overflow pipe 13 at the top of the column 1 and are removed with the assistance of a second circulatory system. In this system, the mixture of solvents is cooled in a heat exchanger tank 14 to approximately 30 C, the cooling being effected by a second evaporator coil 15 supplied from the condensing unit 3. The cooled solvent mixture is drawn from the tank 14 by a pump 16, passed through a filter 17, to remove any frozen water particles, and injected at 18 into the top of the column 1. The mixture flows through the overflow pipe 13, which is provided with a cock 19, into a small header 20 connected to the tank 14. The ice balls 12 from the column 1 are carried through the pipe .13 with the solvent mixture, but are retained in a collecting pan 21 above the header 20. Periodically, the ice balls are removed from the pan 21 and hardened off in a deep freeze cabinet maintained at a temperature of about 20 C.

The diameter of the ice balls thus produced is consistent and, with an internal jet diameter of 1.2 mm., is approximately 6.0 mm. lce balls of smaller or larger diameter can be obtained by using a smaller or larger jet di-' ameter, generally within a range of 1.0 to 1.5 mm.

When the ice balls have been hardened off, they are transferred to the apparatus illustrated in FIGS. 2 to 4,

prises four or more full turns in the roller 24. The two parallel horizontal rollers 22,24 are driven in the same direction (clockwise. in FIG. 2) by electric motors 25,26 whose speeds (up to 200 rpm.) are separately controllable by controllers 27,28. The rollers may a1 ternatively be driven from a single motor through a gearbox.

The ice balls are placed in a lagged refrigerated hopper 29 which has stirring means (not seen) driven by a motor 30. From the hopper 29, the ice balls pass down a feed tube 31 from the lower end of which they are fed singly and intermittently to a point above the bight between the rollers 22,24 by a slidable dispenser rod 32 which is moved in the operative direction by a cam 33 on a disc 34 driven in synchronism with the roller 24 by the motor 26 and is returned by a restoring spring 35. A baffle plate 36 (notshown in FIG. 2) ensures that each ice ball falls into the starting points of the helical groove. It is then carried by the latter, in the bight between the rollers, across the face of the roller22, whose grooves serve not only to carry wax and deposit it on the surface of the ice ball, but also to cause the ice ball to rotate and thus to become well coated with the wax all over its surface.

An alternative means for feeding the ice balls to the coating apparatus is shown in FIGS. and 6. The balls are fed from a vibratory bowl feeder into a tube 38 contained in a thermally insulated enclosure whose temperature is kept below freezing point by means of continuously circulating cold dry air. This effectively prevents the tube 38 from becoming blocked due to accumulation of ice particles. From the bottom of the tube, the balls are transferred to the coating rollers 22,24 by way of a rotating disc 39 provided with a ring of holes 40. The balls'fall in turn into the holes 40 but are prevented from passing at once through the holes by a fixed plate 41. They fall from the disc 39 into the helical groove of the roller 24 at the point 42, where the plate is cut away.

When an ice ball 12 thus coated has progressed to the outer end of the helical groove it falls over a lip 36' or down a guide into a shallow trough 37, through which cold water from inlets 38 is flowing. As illustrated, there may be a second trough 39 to which the ice balls fall down a chute 40. Finally, the ice balls pass down a further chute 41 for collection and storage, the water being carried away by a drain 42. By this stage, the wax coating has solidified and hardened, so that it is immaterial if the ice balls have already reverted to the liquid state.

With the above-described apparatus, spherical wax capsules of consistent size can be obtained at a rate of 120 per minute with the rollers 22,24 rotating at 120 rpm. The coating material used is a mixture consisting of percent of a wax-resin known by the trade name Surfowax 220H (produced by Campbell Technical Waxes Limited) and 75 percent of normal paraffin wax having a melting point of 65 to 68 C.

As an alternative for the solvent mixture referred to above, use may be made of other homogeneous mixtures of solvents, such as carbon tetrachloride and petroleum ether, having a specific gravity within the range of 1.02 1.20 at room temperature, these mixtures being maintained at a substantially constant temperature which is below the melting point of the liquid to be encapsulated. In place of the heat-exchanger 14, 15, the solvent mixture may be circulated through a cooling coil which may itself be cooled by solid carbon dioxide. The frozen liquid balls may be separated from the solvent mixture by a filtering screen preceding the cooling element of the circuit for that mixture.

The invention can be employed for the encapsulation of liquids other than water, for example solutions of salts and other substances, and for the production of capsules serving a variety of purposes, for example smoke-filtration, smoke-flavour improvement and the like.

We claim:

1. An apparatus for encapsulating a liquid comprismg:

a container having a coolant liquid disposed therein;

a conduit coupled to said container at one end for feeding said liquid to be encapsulated into said container;

means associated with said container for introducing overflow coolant adjacent its other end whereby said coolant in the major portion of said container remains static;

said coolant liquid having a lower freezing point than said liquid to be encapsulated;

means associated with said container and said coolant liquid for lowering the temperature of said coolant liquid below the freezing point of said liquid to be encapsulated;

metering means coupled to said conduit for portionwise feeding said liquid to be encapsulated through said static coolant to form uniform frozen spherical solid entities;

discharge means at the opposite end of said container from the conduit through which the overflow coolant and frozen solid entities are discharged; and

coating means associated with said container so that upon discharge of said frozen solid entities a layer of encapsulating material is coated around the entire outer surfaces of the frozen entities which, when hardened, forms an encapsulated rupturable container.

2. The apparatus of claim 1 wherein said container is elongated and has disposed therein cooling conduits coupled to a condensing unit for lowering the temperature of the coolant liquid below the freezing point of said liquid to be encapsulated disposed in said container, said coolant liquid being substantially immiscible with and having a substantially lower freezing point and being of greater density than the liquid to be encapsulated.

3. The apparatus of claim 2 wherein said overflow coolant is collected in a container and having disposed therein cooling conduits coupled to said condensing unit to maintain the overflow coolant liquid at a temperature below the freezing point of the liquid to be encapsulated.

4. The apparatus of claim 1 wherein said conduit means is coupled to an inlet opening disposed in the bottom of said container, said conduit means having heating means positioned adjacent said inlet opening to prevent said liquid from freezing prior to its introduction into said coolant liquid. 

1. An apparatus for encapsulating a liquid comprising: a container having a coolant liquid disposed therein; a conduit coupled to said container at one end for feeding said liquid to be encapsulated into said container; means associated with said container for introducing overflow coolant adjacent its other end whereby said coolant in the major portion of said container remains static; said coolant liquid having a lower freezing point than said liquid to be encapsulated; means associated with said container and said coolant liquid for lowering the temperature of said coolant liquid below the freezing point of said liquid to be encapsulated; metering means coupled to said conduit for portion-wise feeding said liquid to be encapsulated through said static coolant to form uniform frozen spherical solid entities; discharge means at the opposite end of said container from the conduit through which the overflow coolant and frozen solid entities are discharged; and coating means associated with said container so that upon discharge of said frozen solid entities a layer of encapsulating material is coated around the entire outer surfaces of the frozen entities which, when hardened, forms an encapsulated rupturable container.
 2. The apparatus of claim 1 wherein said container is elongated and has disposed therein cooling conduits coupled to a condensing unit for lowering the temperature of the coolant liquid below the freezing point of said liquid to be encapsulated disposed in said container, said coolant liquid being substantially immiscible with and having a substantially lower freezing point and being of greater density than the liquid to be encapsulated.
 3. The apparatus of claim 2 wherein said overflow coolant is collected in a container and having disposed therein cooling conduits coupled to said condensing unit to maintain the overflow coolant liquid at a temperature below the freezing point of the liquid to be encapsulated.
 4. The apparatus of claim 1 wherein said conduit means is coupled to an inlet opening disposed in the bottom of said container, said conduit means having heating means positioned adjacent said inlet opening to prevent said liquid from freezing prior to its introduction into said coolant liquid. 